bump to 3.1.2 and update changelog

Author: FinnSetchell

CHANGELOG.md

@@ -2,6 +2,13 @@
 
 ---
 
+## [3.1.2] - 2026-08-19
+
+### Fixed
+- Fixed a possible crash during world generation or `/reload` when a structure with piece-count limits was being placed on several threads at once.
+
+---
+
 ## [3.1.1] - 2026-08-18
 
 ### Fixed

gradle.properties

@@ -4,7 +4,7 @@ org.gradle.daemon=false
 
 # Project
 mod_id=moogs_structures
-mod_version=3.1.1
+mod_version=3.1.2
 mod_name=Moog's Structure Lib
 mod_author=FinnDog
 maven_group=com.finndog.moogs_structures